Personally I'd be concerned about her saying that she has no interest in dating anyone else. She may be one of those people who finds it easier to have affairs rather than putting in the work required to talk everything out and put it all on the table. She's already shown that she will cheat and the desire to be with more than one person doesn't disappear.

There is also the issue that she has been given no other reasonable choice outside of saying "screw you, I'm leaving". It has been made clear that if she wants to date, certainly if she wants to date her bf that her marriage will end instantly. So... what motivation does she have to be honest?